332 MINNESOTA STATE RTICULHOTURAL SOCIETY. 
weather be dry and hot, cover the plants with leaves or grass cut, if 
possible, when the dew is on. It will require from six to seven thou- 
sand plants to set out an acre in the way described. Between the 
ridges a cultivator can be run, and around the plants a hoe or tined 
hoe must be used frequently until the vines cover the ground. 
The sweet potato is sometimes grown in hills three and a half or 
four feet apart.. A single shovel plow is used in marking out the 
hills both ways. Some manure is placed in each hill, and the hills 
made up witha hoe. There is considerable more labor needed in 
this method than where grown in ridges. The ridge method is also 
preferable in this state, because in dry seasons the moisture would 
be retained better. I have tried level cultivation but never had any 
success, the potatoes being few, long and smooth. 
The sweet potato vine very much resembles wild buckwheat. After 
the vines have made some growth, they send out roots which may 
make small tubers, but which always injure the main crop if the 
vines are not lifted occasionally to prevent this rooting. 
DIGGING AND KEEPING.—The vines should not be killed by frost 
before digging, as this may injure the keeping qualities of the 
tubers. If notready to dig and there is probability of frost, the vines 
should be cut off, and the potatoes dug afterwards. Advantage of 
dry weather should be taken in digging, and those to be wintered 
should be carefully handled, not breaking the skin. The tubers 
should be placed thinly ina dry,cool room. A cellar if any way 
damp is nota proper place. For keeping them into or through the 
winter, they should be packed in boxes in fine and perfectly dry 
sand, and placed in a cool and dry room where the temperature 
does not go below 40° nor much above 60°. Sometimes they decay in 
spite of all care, probably from not being sufficiently dry. The sweet 
potato kiln-dried is in better condition to keep over winter. The 
sweet potatoes of 1894 were as sweet and in quality as good as the 
best from the South. In wet seasons the quality might not be so 
good, but in any year they ought to equal those grown in Illinois 
or Iowa. 
From last year’s experience, the yieldis not profitable, but in 
comparison with that of the common potato, the result should not 
be discouraging. Since the Burbank Seedling in 1891 yielded on an 
adjoining lot at the rate of only 25 bushels to the acre and in other 
years 150 to 200 bushels, it would not be fair to judge either by last 
year’s crop. Of the 1000 vines planted, at least one-third were 
killed by the heat and dry weather in July and August. There was 
gathered five bushels, large and small, which would make a yield 
of 50 bushel to the acre; nearly one-half were very small; on one vine 
were eighteen potatoes, six being large. The annual importation of 
the sweet potato into this state must amount to a great many 
thousands of bushels, and the money sent out of the state for a 
product which there is every probability can be profitably grown 
here in many locations amounts to a large sum. 
